Thread: Scope setup help please

So I’ve just set up my new rig, a Model 7 in 7mm WSM with a Meopta Meopro 6-18x50. I had the option of a 20MOA rail, which I thought would be good to give plenty of elevation adjustment at longer ranges.

When I bore-sighted it, I had to dial the scope down as far as it would go... okay so far, but the first few shots were 10” high at 100m.

I’m thinking I may have to ditch the rail and get some standard bases, but as I’ve blown my budget already, I thought I should see what the gurus on here suggest first.

Could opt for a couple of shims? Tin snips and a empty beer can...

I did try that... didn’t seem to make any difference to the bore-sighting, but I haven’t confirmed that on the range.

Rookie question - shims under ring base or between rail & action?

Whats the total available elevation in the scope?? 20moa Base is 5.8mil

Originally Posted by mopheadrob

So I’ve just set up my new rig, a Model 7 in 7mm WSM with a Meopta Meopro 6-18x50. I had the option of a 20MOA rail, which I thought would be good to give plenty of elevation adjustment at longer ranges.

When I bore-sighted it, I had to dial the scope down as far as it would go... okay so far, but the first few shots were 10” high at 100m.

I’m thinking I may have to ditch the rail and get some standard bases, but as I’ve blown my budget already, I thought I should see what the gurus on here suggest first.

Is it a 4 hole base? I have got a new 0MOA rail here for a Rem M7 - you can square me up when you have the dosh sometime if you want it. $85 inc postage.

Sounds like the scope doesn't have enough elavation adjustment to be able to zero with the 20 moa base.

Ie if the scope had 50 moa total elavation adjustment. Thats 25 down from middle and 25 moa up.

So in theroy with a 20 moa rail you will need to wind 20 moa down to zero it, giving you the extra 20moa of up elavation over and above the 25moa you already had. So total of 45 moa of up elavation available.

But if the scope has 40moa or less of total adjustment you will strike problems getting it zeroed.

Silly question - but have you hit the zero stop?

Originally Posted by GWH

Sounds like the scope doesn't have enough elavation adjustment to be able to zero with the 20 moa base.

Ie if the scope had 50 moa total elavation adjustment. Thats 25 down from middle and 25 moa up.

So in theroy with a 20 moa rail you will need to wind 20 moa down to zero it, giving you the extra 20moa of up elavation over and above the 25moa you already had. So total of 45 moa of up elavation available.

But if the scope has 40moa or less of total adjustment you will strike problems getting it zeroed.

@GWH 42 MOA of elevation (total) https://www.meoptasportsoptics.com/e...o-6-18x50-643/

Correct guys, 40MOA total. Don’t think it has a zero stop, @Tahr. Good points @Mauser308 - I’ll check the fit of the rail, but I wasn’t sure if it was wise to have the scope bottomed out anyway and you’ve confirmed that.

Greetings Mopheadrob,
Quite a common problem with 25.4 mm tube scopes and high magnification. To save spending any more dosh you could try shimming the front end of the rail between the rail and the receiver ring. I don't think a beer can is going to cut it however. A bit of 0.75 mm aluminium flashing is probably going to be needed. You can calculate the thickness needed easily enough. You should be able to get an off cut of 0.75 aluminium from a roofer or plumber. I used some recently to shim the front ring on a Pecar scope. All the best.
Grandpamac.

Scope only has 42MOA of adjustment.
In a perfect world it could only just be zeroed at 100 with a 20moa rail, if everything lined up perfectly, with a whole 2moa to spare - but that is rarely the case.

Bore would need to be perfectly concentric with everything else in order to zero it at 100 and have the theoretical 22 moa remaining elevation usable. It rarely ever works out perfectly, it can go either way (more or less remaining) depending on how the particular firearm is put together.

In order not to run into any surprises, and zero a scope at 100 with a 20MOA rail - a scope should really have 50+ moa of elevation (preferably more) to ensure it can actually be zeored once manufacturing tolerances (in the rifle) are factored in.
Would suggest either a 0, or 10MOA base.

I actually had something similar last month when I was setting my model 7 up with a new Swarovski.

Couldn't get enough windage due to the limited adjustment associated with the 1" Z5.

Solution for me was to get a set of burris signature zee rings with the adjustment inserts in them. Are a decent price and save you having to shim and put more pressure on the scope. Think you can get up to 20MOA inserts which would more than deal with the 10 inch issue at 100m

this is why i went to a 30mm tubed scope, so much more adjustment. i have it fitted on a 20 MOA rail on a 7mmRM and theres still way more adjustment to be had

Lots of good advice as usual...

Yeah, I'd figured you meant the front end, @Mauser308 back pain is a bitch, I hope it improves soon.

Yep, rail's the right way round @berg243... I guess it pays to check, but it if was I would assume I'd have the opposite problem with the rifle shooting low and the scope running out of upwards adjustment.

I'll see if I can find some 0.75mm aluminium @grandpamac, but I think @ChrisW is right and I need to go for a different base. I'm planning to zero at 200, which should mean 1.6" high at 100. That means I need to come down 8.4MOA at least, so a 0MOA base should get me up a bit from the bottom of the scope's range but still leave plenty of elevation.

I'll take @Tahr up on his offer if I can find a taker for my current rail at around the same money. I guess I could keep my eyes out for some M7 Talleys, but they'd need to be high to accommodate the 50mm objective and I like the idea of a rail on a magnum to stiffen everything up

Thanks guys!

Thats fine. Its an EGW (never used). Send me your address and I will get it to you. Worry about the niceties of payment later when you can afford it.